Polycarbonate resins are thermoplastic resin formed by condensation-polymerization of an aromatic diol such as bisphenol A with a carbonate precursor such as a phosgene and have excellent impact strength, dimensional stability, heat resistance, and transparency. Thus, the polycarbonate resins have application in a wide range of uses, such as exterior materials of electrical and electronic products, automobile components, building materials, and optical components.
Recently, in order to apply these polycarbonate resins to more various fields, many studies have been made to obtain desired physical properties by copolymerizing two or more aromatic diol compounds having different structures from each other and introducing monomers having different structures into a main chain of the polycarbonate.
In particular, studies for introducing a polysiloxane structure into a main chain of the polycarbonate have been undertaken.
However, most of these technologies have disadvantages in that economic efficiency is deteriorated due to high production costs, and when chemical resistance or impact strength of the polycarbonate resin is improved, YI (yellow index), etc., are deteriorated.
Meanwhile, a general polycarbonate resin has poor flame retardancy corresponding to a V-2 rating according to UL 94 V Test (vertical burning test).
However, exterior materials of electrical and electronic products, automobile components, etc., generally require high flame retardancy of a V-O rating.
Accordingly, in order to manufacture a polycarbonate-based resin product satisfying high flame retardancy of a V-O rating, a flame retardant should be used.
In general, the flame retardant applied to the polycarbonate-based resin includes a bromine-based flame retardant, a metal salt flame retardant, a phosphorus-based flame retardant, etc.
Among them, the bromine-based flame retardant is classified into environmental hormones and carcinogenic materials, such that the use of the bromine-based flame retardant is regulated. The phosphorus-based flame retardant having excellent flame retardancy for its cost has been the most largely adopted.
However, when the flame retardant is applied, impact resistance and heat resistance of the polycarbonate-based resin are relatively deteriorated, such that an amount of the flame retardant to be required should be limited.
Therefore, there has been a limitation in that a balance needs to be found between flame retardancy and other physical properties at an appropriate level together with securing flame retardancy of the polycarbonate-based resin until now.
As described above, a technology for simultaneously improving other physical properties in trade-off relationship with the flame retardancy of the polycarbonate-based resin has been urgently demanded.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.